Hydraulic turbine



March 10, 1925- W. M. WHITE HYDRAULI C TURB INE Filed July 18, 1921 vBe-it known that WILLIAM Patented Mar. 10, 1925.

PATENT OFFICE.

Wm H. WHITE, OI IQIILWAUKEE, WISCONSIN.

HYDRAULIC TURBINE.

I Application filed July 18, 1921. Serial No. 485,522.

To all whom it may concern:

a citizen of the United States, residing at "Milwaukee, in the county ofMilwaukee and State of Wisconsin, hasinvented a certain new and usefulImprovement in Hydraulic Turbines, of which the following is aspecification.

This invention relates in general to improvements in the art ofconstructing hydraulic machinery, and relates more specifically to animproved hydraulic machine structure and to an improved method ofmanufacturing hydraulic impellers.

An object of the invention is to provide a hydraulic machine which issimple in constructlon and efficient in operation. An-

other object of the invention -is to provide an improved method ofmanufacturing im- Lpellers for hydraulic machines. A further object ofthe invention is to provide simple and eflicient means for preventingdestruction of hydraulic impellers by pitting or wear, and for effectingrepair ofpitted or worn impellers. These and other objects andadvantages of the presentinvention will be apparent from the followingdescription.

It has been found desirable in the art of converting hydraulic energyinto useful work, to operate the rotors or impellers at relativelyighspeed. In order to insure suflicient strength in impellers of hydraulicmachines operable at high speed, it is desirable to construct theimpeller of one piece,

that-is, with the hub, vanes and rim formed' integral. The efiicientoperation of hydraulic machines at highspeed also necessitates formationof the hydraulic passages between impeller vanes, of such shapethatpitting or wear occurs at local. spots ,on the leading vane facesnear the discharge end of the impeller, and is likely to occur at placeswhere eddies may form. The pitting is sometimes augmented by thepresence of sand and gravel in the water and generally occurs" atsubstantially the same place on each of the successive impeller vanes.

In order to-avoid necessity of replacing an entire impeller or the vanesthereof, due to pitting or wear, the present invention contemplates the-prov1sion of simple and eflicient means for appreciably eliminatingpitting of the turbine vanes and for permitting rapid repair of pittedimpellers in cases .-.where tplitting cannot be entirely eliminated.

With

e present invention the impeller is M. Wears,

recesses. When pitting or wear occurs in v be qickly and convenientlyrepaired at minimum cost, and with minimum loss of operating time.

A clear conception of an embodiment of the invention and of the improvedmethod of manufacturing impellers, may be'had by referring to thedrawing accompanying and forming a part of this specification in whichlike reference characters designate the same or similar parts in theseveral views;

Fig; 1 is a central vertical section through a hydraulic turbineimpeller of the Francis type, showing local wear plates applied to thevanes. Fig. 2 is a fragmentary bottom view of the hydraulic impellerprovided with local wear plates, looking at the delivery end of theimpeller.

Fig. 3 is a developed vertical section through-the impeller vanes andthe wear an impeller so constructed, the impeller may plates, thesection being taken along theline as specifically applied to a Francistype of impellerit will be obvious that the principles are moregenerally applicable to other types of hydraulic impellers. The Francisimpeller'comprises in general a central hub 2, an annular series ofvanes 3 formed integral with the hub 2, and. an outer rim 4 secured tothe outer extremities ofthe vanes 3. The one-piece im eller ispreferably formed by casting an the hub 2 is bored for attachment to amain shaft 5. The hub 2 has a generally conical. contour whereby. thewater is properly ided throfi h the impeller, and the end 0 the hub 2adjacent to the impeller discharge may be provided with a removable cap6 as shown. Each of the impeller vanes 3 is curved and is provided wittapered discharge end 10 of the nnpeller.

a local recess havmg' Located within each of the recesses of theimpeller vanes 3, is a wearing plate 7 the outer surface of which isflush with the adjacent surface of the vane 3 thus forming a smoothsurface for guiding the water. The weal-plates 7 may be attached to the,rectly into the vane recesses.

vanes 3 either with the aid of cap screws 9 as shown, or by riveting, orby spot welding, or by caulking, or by casting the metal di- The wearplates 7 may also be formed either of the same or of different materialthan that of the impeller vanes. It may in some cases be desirable toform the impeller. vanes of cast iron and to employ steel or bronze Wearplates. The recesses in the vanes 3, may also belocated at variousplaces and each vane may if desired be provided with more than onerecess and wear plate 3 therein depending upon the impeller design.

3 thereof, are preferably formed by casting, the wear plates 7 beingsubsequently a plied. The wear plates should, however,

made readily detachable, in orderto permit rapid and convenient renewalthereof. By

thus forming the impeller and the wear plates, the cost of repair of theimpeller is reduced to a minimum and minimum loss of operating time ofthe unit is entailed by such repair. By embedding the wear plates Withinthe impeller vanes, these plates may be effectively secured against dislacement by centrifugal force and smooth hydraulic tendencyof pitting isslight, the wear plates may be'fiermanently secured to. the impellervanes, t e plates being formed of maternal capable of more readilyresisting the pitting action. v

It should be understood that it is not desired to limit the presentinvention to the exact details of the structure and of the method ofmanufacturing impellers, herein shown anddescribed, for variousmodifications within the scope of the appended claims may occur topersons skilled in the art. 1

It is claimed and desired to secure by Letters Patent:

1. In a hydraulic turbine, an impeller comprising-a series of vanes eachhaving a face subjected to liquid pressure and having an opposite facesubjectedto suction during normal operation of the turbine, each of esaid vanes being initially formed with a The impeller and the recessesin the vanes.

local' recess in its suction face at the discharge end of the pressureface of an adjacent vane, and a renewable wear plate secured'to each ofsaid vanes within said recess. 7 p

2. In a hydraulic turbine, an impeller having ahub and a series of vanesformed integral with said hub, each of said vanes having a, facesubjectedtoliquid pressure and having an opposite face subjected to Isuction during normal operation of the tu1'-' bine and each of saidvanes being. initially formed vwith a local recess in-its suction faceat the discharge end 'of the. pressure face of an adjacent vane, andaren'ewable wear plate secured to each ofsaid vanes' within said recessand having awearing surface substantially flush with the adjacentsuction face of the vane. s In testimopxwhereof, the signature of theinventor is 'ed' hereto. Y

WILLIAM M. WHITE;

